Is this really what we can see?

General discussion about Celestia that doesn't fit into other forums.
Avatar
Topic author
jogad
Posts: 458
Joined: 17.09.2008
With us: 16 years 2 months
Location: Paris France

Is this really what we can see?

Post #1by jogad » 20.09.2008, 16:48

Hello

Image

Show in Celestia

Look at the picture above.
It shows a view of Saturn from space on Christmas Day in 2002.

At that time the ring is very inclined on the orbit and aligned so that sunlight strikes it from the south.

On the image the sunlight comes from the right and we can see the shadow of the ring on the north hemisphere of the planet.

So the side of the ring that we are looking at is the north side and is not illuminated by the Sun.

Thus I think the ring should be invisible or at least very dimly lit.

What is your opinion about that?

Avatar
selden
Developer
Posts: 10192
Joined: 04.09.2002
With us: 22 years 2 months
Location: NY, USA

Re: Is this really what we can see?

Post #2by selden » 20.09.2008, 17:04

The real rings are not solid objects. They're a collection of many tiny objects.They don't cast shadows on one another and you can see the sunlit hemispheres of all of them. Although Celestia draws the rings as a single object, if you move your viewpoint around Saturn, you will see the ring brightness vary: the shadowed sides of the rings are darker when your viewpoint is on the dark side of Saturn. The variations aren't quite right, though. I believe that Chris L. is planning to improve the ring illumination algorithm for v1.7 of Celestia.
Selden

Avatar
Topic author
jogad
Posts: 458
Joined: 17.09.2008
With us: 16 years 2 months
Location: Paris France

Re: Is this really what we can see?

Post #3by jogad » 20.09.2008, 17:24

Selden, thank you very much for the quick response concise and precise.

:D I was a little afraid that the level of this forum reserve it for the specialists and I am glad to see that it’s not.

Jogad

Avatar
selden
Developer
Posts: 10192
Joined: 04.09.2002
With us: 22 years 2 months
Location: NY, USA

Re: Is this really what we can see?

Post #4by selden » 20.09.2008, 17:44

You're very welcome.
Selden


Return to “Celestia Users”